CONDENSED CONSOLIDATED STATEMENTS OF CASH FLOWS (Unaudited) - USD ($) $ in Thousands	6 Months Ended
	Jun. 30, 2023	Jun. 30, 2022
CASH FLOWS FROM OPERATING ACTIVITIES:
Net Income (Loss)	$ 21,668	$ 102,072
Adjustments to reconcile net income to net cash provided by operating activities:
Depreciation	17,653	17,174
Amortization of intangibles	1,086	1,328
Loss on disposal of property and equipment	22	1,034
Stock-based compensation expense	14,120	12,692
Amortization of premium on marketable securities	419	1,867
Deferred income taxes	(2,782)	(3,282)
Increase (decrease) in accounts receivable allowance for credit losses	(454)	259
Change in operating assets and liabilities:
Accounts receivable	(10,787)	13,154
Inventories	(14,321)	(11,992)
Prepaid expenses and other assets	(7,241)	4,075
Accounts payable	8,813	5,577
Taxes payable and accrued liabilities	(5,430)	(2,539)
Net cash provided by operating activities	22,766	141,419
CASH FLOWS FROM INVESTING ACTIVITIES:
Purchases of property and equipment	(7,211)	(27,944)
Proceeds from sale of property and equipment	0	1,202
Purchases of marketable securities	(110,810)	(20,710)
Proceeds from sales and maturities of marketable securities	98,641	125,527
Net cash provided by (used in) investing activities	(19,380)	78,075
CASH FLOWS FROM FINANCING ACTIVITIES:
Issuance of common stock under employee stock plans	3,098	3,057
Repurchase of common stock	(5,999)	(292,349)
Payments of dividends to stockholders	(21,761)	(20,936)
Net cash used in financing activities	(24,662)	(310,228)
NET DECREASE IN CASH AND CASH EQUIVALENTS	(21,276)	(90,734)
CASH AND CASH EQUIVALENTS AT BEGINNING OF PERIOD	105,372	158,117
CASH AND CASH EQUIVALENTS AT END OF PERIOD	84,096	67,383
SUPPLEMENTAL DISCLOSURE OF NON-CASH INVESTING AND FINANCING ACTIVITIES:
Unpaid property and equipment	2,713	2,984
SUPPLEMENTAL DISCLOSURE OF CASH FLOW INFORMATION:
Cash paid for income taxes, net	$ 11,653	$ 14,657